An electric vehicle that travels by a driving force of an electric motor cannot use waste heat of an engine at the time of heating, since the engine is not mounted thereon. Further, the amount of heat at the time of heating is not enough even in an electric vehicle on which the engine is mounted, such as a hybrid vehicle, since it does not operate the engine at all times. For this reason, an air conditioning device that is formed by a refrigerant cycle having an electric compressor is used at the time of heating, so as to increase temperature inside a cabin.
However, power accumulated in a battery is consumed by the amount used for operating the air conditioning device, which results in a reduction in cruising distance of the vehicle.
JP2011-68348A discloses an air conditioning system provided with a heat exchanger that has a cooling water circuit for cooling a battery, in addition to a refrigerant cycle forming an air conditioning device, and that can exchange heat between the refrigerant and the cooling water. According to this air conditioning system, the battery is heated at the time of charging, and the heat stored in the battery is used when the vehicle is in operation and when the heating is used.